How does the "disable" feature for Fupla pages work?

FAQ #101366

 

Although a user program page in Fupla editor is disabled it can generate errors and warnings. This is due to the fact that all pages get compiled even if disabled.
During compilation the disabled part gets a preceding jump instruction. Once loaded into the PCD this instruction directly jumps to the end of the disabled code part. So albeit the disabled code is present in in the final user program it will never be executed.